1. Field of the Invention
The invention concerns a process and a means for disintegrating compressed material bales of coarse, fiber-like natural or synthetic materials, especially straw bales, and for sending the disintegrated fiber materials on for their intended further processing.
Mats are used to protect against erosion at many locations. They prevent erosion of dirt on large open areas, such as those remaining after earth-moving operations. They also protect areas of earth fill and accelerate plant growth on them. Building regulations may require that such mats be used to protect the ground. These anti-erosion mats are made of a net-like supporting layer and a fiber layer of synthetic or natural fibers such as coconut fibers or straw, which are combined in special machines using sewing, stitching or linking machines, which are themselves known.
Straw bales in particular often contain foreign objects such as stones, pieces of wood, pieces of metal or other contaminants which are picked up by the straw balers when the straw is recovered and which are compressed into straw bales together with the short and long straw. When the bales are broken up, these foreign objects and contaminants are also removed. They accompany the flow of fibers of long and short straw to a transport auger. At the outlet of the auger there is a radial blower which moves the broken up and separated materials to the machines and systems which process the straw into anti-erosion mats. In that feed process, the foreign objects and contaminants gain very high kinetic energy, so that they cause substantial damage to the feed equipment and the production equipment, and to the product itself. Long down-times and losses of production are unavoidable consequences.
2. Related Art
Processes and means for removing fiber flocs from a bale of textile fibers, such as cotton or synthetic fibers, are already generally known. They are described in, for instance, DE 41 20 818 A1 and DE 44 22 574 A1.
A device for opening and mixing of fiber bales is known from DE OS 24 16 944. With that device, the fiber bales are broken down with a toothed or wire roller. Then the fiber flocs are moved to a discharge space. They are moved out of that space by means of an air flow produced by blowers through a discharge line to a collector or to a machine for further processing of the fibers. In the discharge space there is a transport auger which slopes up to the discharge line so that the fiber flocs are carried away without damage, independently of the position of the discharge line.
DE OS 29 14 576 describes a device for opening a fiber bale and separating the fibers, in which the fibers are again abraded from the bales by suitable grinding tools. A pneumatic feed is provided to move the fibers falling from the grinding tool in their separated state to a discharge funnel. The pneumatic feed comprises a perforated floor plate through which the air flows and which transports the fibers to a discharge funnel. All the suggested solutions refer to separation and removal of cotton fibers and similar fibers, which have relatively low masses and so can be transported relatively easily to the machines and systems for their further processing. Furthermore, those fibers are removed from fiber bales which are relatively free of foreign objects and contaminants. Therefore these solutions are not usable or transferable to solve the problem initially stated.
According to DE 36 44 535 A1, the separated fiber flocks are piled loosely on a conveyor belt, and that pile is examined with an electronic device that searches for foreign objects, to detect foreign objects such as foreign fibers, binding twine, plastic tapes, wires, and the like. On detection of a foreign object, means are activated which remove the portion of the pile of flock in which the foreign object has been detected from the loose fiber pile. This suggestion assures exact detection of foreign objects, but the equipment is relatively expensive. The relatively high cost is not in proportion to that of the relatively simple machines and systems used to process straw into anti-erosion mats. Aside from that, there are heavy dust loads when straw bales and straw are processed. That requires extra protection of the electronic components of such a foreign object detection device. The solution of DE 36 44 535 A1 is not usable for systems and equipment for producing anti-erosion mats using natural or synthetic fibers compressed into bales.
DE 40 38 685 A1 describes a means for processing bales of staple fiber having contamination, such as oil, clay, and the like on the surface of the bales. According to DE 40 38 685 A1, the cleaning device used for this purpose is in contact with the surface of the bale and can be moved relative to that surface. The cleaning device has a cleaning roll which acts as a high-speed dressing roll and grinds the contamination off the surface of the bale. That solution can only remove superficial contamination from the bale surface. That solution is not applicable for foreign objects and contaminants compressed inside the fiber bale along with the fibers.